Loosely inspired by the DIY Pinewood Derby, I propose a similar contest near the end of the summer:

The Twin Cities Maker Zipline Race-stravaganza!

The plot: Makers entire vehicles in one of three categories: climbers, sliders, and zippers.

- Climbers race uphill on a wire ~50' from start to finish. Wire angle is 30°. Means of locomotion is friction only- wheels on the wire, or a clamp-yank-release mechanism.- Sliders race downhill on the same wire. Means of locomotion is gravity feed only- no thrust or wheels, and no lubrication of the wire.- Zippers travel horizontally on a wire of the same length. Means of locomotion is anything BUT friction on the wire- propellers, compressed air, reaction mass. This group may need some other rules- I have no doubt that our resident rocketeers could sweep this category with little trouble.

This could be a potential moneymaker- nominal awards or whatever with a small entry fee could result in a net TCMaker income from it. I'd suggest late summer- say, mid or end of August (despite the heat) as a time.

This is a pretty sweet concept. The zipper "rocket powered" dragsters would be quite the spectator sport. Thou, that suggests its an outdoor event. Maybe we should think about renting a pavilion somewhere.

I remember this being a Cub Scouts thing (like Pinewood Derby). We built rubber-band-powered 'rockets.'

I'd say for race #3 'no combustibles on board.' That way no one can take the easy way out and use model rocket engines -- you'll have to come up with something else (compressed gas, steam, propeller(s), etc).

For the third group, I was trying to suggest that we put limitations on it- probably no reaction mass. It would be unfair to put propeller drive against reaction mass.

My inclination at this point is to try and have this in a backyard. Failing that, a public park would be a good option. Most likely, we could get a largish pavilion and do it there- if it's large enough we might fit the whole course inside.

There is a park over by ford (plant) parkway by the river. that has some pavilions with some space between. maybe run the course between those pavilions so spectators could set up in one, and contestants could have a staging area in the shade.

i like this... is 50' too long? should we do a few proof of concept things ourselves to determine what kind of cable we want to use and length?

say 1/8 or 1/16" steel cable? a "stock" item.

we also need to spec if you can feed onto the end of the line or if ends are fixed and you need to attach in the middle of the line.

30` pitch may be a litle severe, iirc that's about a 9:12 which would be something like a 35' drop, far les trivial to engineer the rig than say a ~12' drop which we could do say from the top of a garage, or convienient tree trunk.

metis wrote:30` pitch may be a litle severe, iirc that's about a 9:12 which would be something like a 35' drop, far les trivial to engineer the rig than say a ~12' drop which we could do say from the top of a garage, or convienient tree trunk.

I could do it. I can even think of 2 more TC Makers (at least!) who could help. (Not that I disagree with you on this; it's just I haven't busted out my climbing gear for a while, and this sounds like a perfectly good excuse.)